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Comment by velox_io | Hacker News Reader

That does make sense, especially for IoT devices (literally anything low power). However, I haven't seen PoE used outside of business use. The problem is that Wifi is becoming ever more prevalent (on my network I have 12 devices using wifi, and only my desktop using an ethernet cable - ironically the only device that isn't suitable for PoE).

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I use PoE UniFi gear, because running a single Ethernet cable to power e.g. a wifi AP gives me a lot more flexibility in placing it cleanly than having to worry about power; that's for residential use.

Given the degree of fire risk in houses that's associated with 230V/10A wiring and devices, I do wonder how much safer it would be to have fewer AC/DC transformers scattered around the house with DC wiring.

If you're using DC to transmit the same amount of power, you'll probably be using similar voltages (otherwise you're going to need thicker cables). I suspect DC is probably a greater fire risk in this case due to arcing. An arc is less likely to persist on AC since the potential keeps passing through 0 V (hence DC switches are designed to have a bigger air gap).

If it's just a matter of providing alternative circuitry for low-power devices, presumably you can already improve safety by just using lower-current circuit breakers.

> If you're using DC to transmit the same amount of power, you'll probably be using similar voltages (otherwise you're going to need thicker cables).

A good point - I guess I'm mostly thinking about the volume of things in the house that don't really need access to even a fraction of the 2.4kW available; having moved from incandescent bulbs to LEDs, I've got a bunch of unnecessary power supply and per-bulb transformers, for example.

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